Interferon-inducible gene (lymphocyte antigen 6 complex locus E) as a biomarker of disease activity in systemic lupus erythematosis patients

Abstract Aim of the work: To assess the expression of type I interferon (IFN) inducible gene (Lymphocyte antigen 6 complex Locus E) in patients with SLE and to correlate expression Level with disease affair and/or severity. Patients and methods: Peripheral blood samples have been collected from 40 patients with SLE patients and 25 healthy donors as a control. Total RNA was extracted and reverse transcribed into complementary DNA for all samples. Level of expression of interferon-inducible gene LY6E was measured by real time polymerase chain reaction (PCR), after which gene expression comparisons were performed between SLE patients and control subjects. Disease status was assessed according to the systemic lupus erythematosis disease activity index (SLEDAI) and systemic lupus international collaborating clinics/American college of rheumatology damage index (SDI). Results: Type I Interferon-inducible genes (IFIGs) lymphocyte antigen 6 complex locus E (LY6E) was highly expressed in SLE patients compared with normal controls. Type I IFIGs (LY6E) was positively correlated with the SLEDAI scoring degree. Elevated Type I IFIGs (LY6E) was also correlated with the presence of cumulative organ damage (Systemic Lupus International Collaborating Clinics/ American Society of Rheumatology Damage Index).Type I IFIGs (LY6E) was positively correlated with anti-double stranded DNA (anti-dsDNA) antibodies and negatively correlated with C3. LY6E level were positively correlated with proteinuria degree. Conclusion: Type I IFIGs (LY6E) was highly expressed in SLE patients, the higher expression of LY6E gene in patients with SLE is closely associated with disease activity, degree of organ damage, proteinuria, and with anti-dsDNA antibody positivity titer and hypocomplementenemia. The LY6E may be a prospective biomarker to judge lupus activity clinically